To make the buttermilk dressing, whisk the mayonnaise, sour cream, and buttermilk in a medium bowl. Add the chives, dill, garlic, shallots, and lemon juice and whisk again. Season to taste with salt and pepper. Bring a large pot of well-salted water to a boil, add the pasta, and cook according to the package directions. Drain the pasta and immediately run plenty of cold water over it until it is completely cool. Drain well. Put the pasta in a large bowl, and, using a rubber spatula, fold in enough dressing to coat it generously. Fold in the scallions, cheese, and ma^che or spinach leaves.

Mound the salad on a large platter and serve. Makes 6 servings.

Make ahead
You can cook the pasta a few hours ahead, run cold water over it, and drain. Spread the pasta in a single layer over a lightly oiled baking sheet. Cover the pasta with plastic wrap and refrigerate. You can make the dressing early in the day and refrigerate, covered. But toss the pasta salad with the dressing only when you are ready to serve.

Tom Douglas is an American executive chef, restaurateur, author, and radio talk show host. He is known for winning the 1994 James Beard Award for Best Northwest Chef. He shared this recipe with us, adapted from his book Tom’s Big Dinners (Morrow, 2003), as part of his appearance on the PBS series Moveable Feast with Fine Cooking airing each Saturday at 1pm on WGBH 2.

For more great recipes from Moveable Feast with Fine Cooking, visit Fine Cooking.